Automated CCHD screening and detection

Automated critical congenital heart defect (“CCHD”) screening systems and processes are described. A caregiver may be guided to use a single or dual sensor pulse oximeter to obtain pre- and post-ductal blood oxygenation measurements. A delta of the measurements indicates the possible existence or nonexistence of a CCHD. Errors in the measurements are reduced by a configurable measurement confidence threshold based on, for example, a perfusion index. Measurement data may be stored and retrieved from a remote data processing center for repeated screenings.